The +2 extension is the perfect length for my needs. Minimal added length, gives 8 rounds on tap and allows a full grip. I wonder if they will send us early adopters a spring. Haven't had any reliability issues but still wouldn't mind a stiffer spring to make sure.
I know some other people called and told them that their G43 wasn't feeding reliably with the +2 (honestly), and TT sent them a new spring.